Venesectrix said:
I'm trying to make some metal chest armor. I've got my templates(thanks to this forum) and a bunch of sheet metal from an old air conditioner.
It's about a millimeter thick..
I was wondering what are some ways to cut the metal.
I tried using a hacksaw, but it looks like that would take really long time.
On one thread I heard to use a jigsaw, but I don't think you can get much precision with that

I've got a dremel, but I wouldn't know what kind of tip to use..
peace,
Venesectrix
Assuming that the metal is mild steel and is about 1 to 1.5 mm thick, it should be fairly easy to cut with a hacksaw or hand-operated nibbler. You could even try heavy tin snips. You can also get hacksaw blades for an ordinary jigsaw.
A trick I have found for using a hacksaw on sheet metal is to clamp the metal between two piece of plywood or MDF, then use the hacksaw at a very low angle, using the lower piece of wood as a cutting line. This stops the sheet metal from vibrating, which stops the teeth from digging in and doing their job as chisels, plus it means that each tooth takes a longer cut as it passes across the surface, say 2 or 3 mm instead of just 1 per stroke.
It has been ages since I used a jigsaw, but it worked OK, although it was harder to get the metal clamped in such a way that it didn't vibrate. Basically, more vibration = less cutting + much more noise.
You can get good results with hand held nibblers, but they are not too easy to come by. I'm not sure how expensive electric nibblers are where you are, but they would work very well. I use a Monodex hand nibbler, which will cope with mild steel up to about 1mm. It's fairly easy to use, but you'll develop a grip like a money lender's dog!
Attached is a photo of the hacksaw set up I use, showing some thin stainless being cut. BTW - don't ever try to cut stainless with anything other than a cutting wheel or a hacksaw - for some reason shears just slip and it even distorts or damages the blades.
It might be worth getting in touch with a local auto bodyshop - they do this sort of stuff for a living and know all the tricks.
Regards, Phil